1. Technical Field
The following description relates to one or more image forming devices such as an electrophotographic copy machine and a printer.
2. Related Art
In an image forming device such as an electrophotographic copy machine and a printer, a laser scanning method and an LED exposure method have been put into practical use as an image writing method (i.e., an exposure method). The LED exposure method is a method in which light emitted by a light emitting unit with a plurality of light emitting elements linearly aligned is directed onto a surface of a photoconductive body with an imaging system and a latent image is formed on the surface of the photoconductive body.
FIG. 10 schematically shows a configuration of a main portion of a known image forming device when viewed in a direction perpendicular to a carrying direction of a recording medium. The image forming device 101 shown in FIG. 10 is configured to perform color printing. In a device main body 102, four drum units 103 are detachably disposed that correspond to yellow (Y), magenta (M), cyan (C), and black (K), respectively, in an order from an upstream side in an arrow D direction as the carrying direction of the recording medium.
Each of the drum units 103 is provided with a photoconductive drum 103a configured to rotate in an arrow C direction. Further, images of the predetermined colors are sequentially transferred onto the recording medium which is conveyed in the arrow C direction while being stuck to a carrying belt (not shown) by the respective photoconductive drums 103a in collaboration with respective transfer rollers 104 rotated concurrently with the photoconductive drums 103a. 
Meanwhile, a stacker cover 107 is rotatably supported by the device main body 102 via a rotational shaft 108 extending in a direction perpendicular to the arrow D direction. Further, the stacker cover 107 holds four LED heads 111 disposed in positions corresponding to circumferential surfaces of the photoconductive bodies 103a of the drum units 103, respectively. Thus, the stacker cover 107 is configured to be opened and closed with respect to the device main body 102, and provided such that the drum units can be replaced when the stacker cover 107 is opened with respect to the device main body 102 (for example, see Japanese Patent Provisional Publication No. 2003-112446).